1. Field of the Invention
The invention relates to an annular seal positionable in a gap that can vary in size.
2. Description of Related Prior Art
In certain operating environments, two adjacent structures can be spaced from another and can change size at different rates. This condition can result in a gap between the structures that varies in size. Spring seals are a known approach to sealing such a gap. Spring seals can also be referred to as seal rings and can take many forms. For example, U.S. Pat. No. 6,419,236 discloses a seal ring which includes a spiral spring wire acting as an expander device that can be inserted inside a C and or U shaped jacket made of a softer material such as an elastomer. The spiral spring wire forces the outer and inner lips of the jacket outwardly and inwardly to create a seal.